A senior U.S. government official said Friday he is not sure when the nearly-completed Sudan peace talks will resume, and he urged the Sudanese government to return to the talks with the country's main rebel group in the south.

The administrator of the United States Agency for International Development, Andrew Natsios, told reporters in Nairobi the Sudanese government has so far given him no assurances about when - or if - it will continue its long-running peace talks with the southern rebels.

"No, they haven't given us those assurances," Mr. Natsios said. "We hope they will. We're saying that's what should happen - we're not saying it's about to happen."

But Mr. Natsios was quick to add he is confident the Sudanese government will eventually resume the negotiations it began more than two years ago in Kenya with the Sudan People's Liberation Army.

The Sudanese government has said it wants to see the peace talks resume and be concluded soon.

Negotiators say only small, technical details remain to be worked out before a final peace deal can be signed that would end more than 20 years of fighting that has killed more than two million people.

The last round of talks adjourned at the end of July, with no indication of when they would resume.

Mr. Natsios and others are concerned that the crisis in the western Sudan region of Darfur, which flared up a year and a half ago, is overshadowing the north-south peace talks and is keeping the government away from the negotiating table.

Mr. Natsios says the implementation of the pending agreement, called the Naivasha Accords, is crucial for achieving peace in the whole country, including Darfur.

"The fact is, the Naivasha accords are a peace agreement that form a foundation for the settlement of all of the political disputes, north and south in Sudan," Mr. Natsios explained. "And if the accords are carried out as they're written, in good faith by all sides, many of the political problems the north is now having with northern provinces outside of Khartoum will be dealt with.

Mr. Natsios is scheduled to visit Sudan on Saturday.

At his news conference, Mr. Natsios also expressed concern that the Darfur war has overshadowed the violence in northern Uganda. There, a rebel group called the Lord's Resistance Army is terrorizing the population, a situation he likens to Darfur.

"The level of atrocities in northern Uganda has just been unspeakable," Mr. Natsios said. "It's as bad as Darfur actually. We've done human rights reports, working with the State Department and the international community - I mean, the atrocities (of) the LRA are just unimaginable."

The Lord's Resistance Army has been kidnapping, raping, mutilating and killing people in northern Uganda for some 17 years.

Mr. Natsios accused the Sudanese government of supporting the LRA, a charge Sudan has denied. But Mr. Natsios also says the Ugandan group is on the decline thanks to recent arrests and surrenders of high-ranking members.